Modular sewing machines



Jan. 7, 1969 R. E. JOHNSON MODULAR SEWING MACHINES Sheet Filed Feb. 3,1966 R. m E V m Ralph E. Johnson BY ZTTORNE Y WITNESS 7, 6 R. E. JOHNSONMODULAR SEWING MACHINES Sheet Filed Feb. 5, 1966 INVENTOR. Ralph EJohnson BY W 9'4 TTORNEY WITNESS 1969 R. E. JOHNSON MODULAR SEWINGMACHINES- Sheet Filed Feb. 5, 1966 INVENTOR Ralph E. Johnson 8) I 42 7mmw/nvsss 1969 R. E. JOHNSON 3,420,200

MODULAR SEWING MACHINES Filed Feb. 3, 1966 iVIII/ I lllll INVENTOR.Ralph E. Johnson ATTORNEY Jan. 7, 1969 R. E. JOHNSON MODULAR SEWINGMACHINES Sheet Filed Feb. 5, 1966 3 N 9 I H 0 I: I. H a 3 V G a o zotomb 5024 x258 5m $35. 955;

INVENTOR. Ralph E. Johnson BY )2 2T TORNE Y WITNESS United States PatentOflice 3,420,200 Patented Jan. 7, 1969 1 Claim ABSTRACT OF THEDISCLOSURE A modular lockstitch sewing machine construction is disclosedin which a frame member having only two accurately machined surfacessupports all of the parts of the sewing machine. A needle moduleincluding a needle thread take-up is located and secured on one of theaccurately machined surfaces and a loop taker module is carried on theother accurately machined surface. A drive module including a rotarydrive shaft is secured on a portion of the frame which is not accuratelymachined. The rotary drive shaft which is opcratively connected toreciprocate the needle and actuate the take-up is supported inself-aligning bearings in the needle drive modules. Wide variations inthe alignment of the rotary drive shaft can be accommodated because thetake-up is formed as an extension of the needle bar drive link.

This invention relates to sewing machines, and more particularly to anovel and improved organization and arrangement of parts in a sewingmachine.

It is an object of this invention to provide a sewing machine in whichthe various instrumentalities are subassembled as separate modules whichmay be fixed in cooperative relation on a simple supporting element.

In the conventional construction of a sewing machine, the sewing machineframe is constructed so as to accommodate the individual relativelymovable elements of the stitch forming instrumentalities as well as theindividual elements of the actuating and control means therefor.

The manufacture of the conventional sewing machine frame, therefore,requires a large number of separate machining operations each involvinga high degree of accuracy. Since an error in any of the many machiningoperations can jeopardize the usefulness of the entire conventionalmachine frame, this mode of sewing machine organization is relativelyexpensive; and moreover, the complexity of the conventional sewingmachine frame is a deterrent to the ready substitution of oneinstrumentality for another in a conventional sewing machine as might bedesirable, for instance, to ready the machine for different types ofsewing operations.

It is an object of this invention to provide a sewing machineconstruction in which none of the relatively movable elements of thestitch forming instrumentalities nor of the actuating and control meanstherefor are accommodated directly in the machine frame. Thisarrangement makes possible a sewing machine frame which requires onlytwo accurately machined locating surfaces; one upon which the sewingneedle module is fixed, and the other upon which the loop taker moduleis located. Over and above these two accurately machined surfaces onlyfastening means requiring a relatively low order of accuracy arerequired in order to accept the actuating mechanism module, supportinglegs, and the like.

Apart from the advantages of simplicity and economy of manufacture, themodular organization of the sewing machine of the present inventionprovides an advantage of increased versatility, in that any of themodules may be readily removed and exchanged for modules particularlyarranged for different specific sewing operations.

It is also an object of this invention to provide novel combinations ofthread manipulating instrumentalities, actuating mechanism, and controlmeans therefor which make possible advantageous organization of thesewing machine parts in modular arrangement.

These novel combinations and the manner in which they contribute to thenovel modular organization of a sewing machine in accordance 'with thisinvention will now be described with regard to a preferred embodimentillustrated in the accompanying drawings in which:

FIG. 1 represents a perspective view of the sewing machine frametogether with the stitch forming instrumentalities, actuating mechanism,and control means therefor in modular form in accordance with thisinvention with each module shown detached from the sewing machine frame,

FIG. 2 represents a head end elevational view of an assembled sewingmachine of the type illustrated in FIG. 1 and including a supportingbase and an electric drive motor,

FIG. 3 represents a hand wheel end elevational view of the assembledsewing machine of FIG. 2, with a portion of the hand wheel broken awayexposing the stitch length adjusting means,

FIG. 4 represents a front elevational view of the assembled sewingmachine of FIG. 2 with portions of the actuating mechanism illustratedin vertical cross section,

FIG. 5 is an enlarged cross sectional view taken substantially alongline 5-5 of FIG. 2 illustrating the work feeding mechanism,

FIG. 6 represents a top plan view of the loop taker module of thisinvention as secured in place on the sewing machine frame,

FIG. 7 is a cross sectional view taken substantially along line 77 ofFIG. 6 illustrating the loop taker,

FIG. 8 is a top plan view of the loop taker of this invention,

FIG. 9 is a top plan view of the bobbin case,

FIG. 10 represents a head end elevational view of an assembled sewingmachine of the type illustrated in FIG. 1 and including a portion of anend cover plate applied thereto together with a representation of thepath of motion of the needle thread take-up eyelet, and

FIG. 11 is a graph indicating the thread demand of the stitch forminginstrumentalities as compared with the thread control attained by thetake-up.

Referring particularly to FIG. 1, the machine frame is indicatedgenerally at 11; the sewing needle module at 12; the loop taker moduleat 13; and the actuating and control module at 14.

The frame 11 comprises a C-shaped member which may be of uniform crosssection and includes a pair of substantially parallel free extremities15 and 16 joined by a connecting portion 17. The frame may be fabricatedin this shape by a bending or forging operation or it may be cast inthis shape. Only two accurately machined surfaces are required on theframe 11 and in the preferred embodiment illustrated in the drawingsthese surfaces are a cylindrical portion 18 turned on the free extremityof the arm 15 to accept the sewing needle module 12, and a slabbedportion 19 milled on the free extremity of the arm 16 upon which theloop taker module 13 is located. The axis of the cylindrical portion 18is preferably parallel to the plane defined by the slatted portion 19and the distance there between is preferably formed to an accuratepredetermined dimension. The frame 11 may also be formed with provisionfor fastenings, such as the tapped holes 20 and 21 illustrated in FIG.1, to accommodate fastening screws 22 and 23 for the actuating andcontrol module 14, the tapped holes 24 and 25 to accommodate fasteningscrews 26 and 27 for the loop taker module 13, and the tapped hole 28 toaccommodate the fastening screw 29 for a supporting block 30 illustratedin FIG. 4. It will be appreciated, however, that other known types offasteners such as clamps might be used in place of these threadedfasteners which would not require any machining of the frame 11 for thefasteners, and the tapped holes 20, 21, 24, 25, and 28 need not belocated with a high degree of accuracy.

The needle module 12 comprises a support plate to the inside surface ofwhich is secured a block 41 formed with a bore 42 which may beaccommodated on the cylindrical machined surface 18 of the frame arm 15.The block 41 is drilled and tapped, as at 43, for a set screw 44 bywhich the needle module 12 may be secured relatively to cylindricalmachined surface 18 in selected axial and angular position thereon.

To the outside surface of the support plate 40 is secured a bracket 45between the out turned arms 46 and 47 for endwise reciprocatory motionis a needle bar 49 carrying at its lower extremity a needle clamp 50 inwhich an eye-pointed thread-carrying sewing machine needle 51 issecured. The upper extremity of the needle bar is transversely aperturedto accommodate a pivot screw 52 which carries a roller 53 which rides ina guide slot 54 in the support plate 40 to prevent turning of the needlebar.

The support plate 40 above the guide slot 54 is formed with concavebearing seat 55 having the shape of a spherical section. Accommodated inthe bearing seat 55 is the spherically shaped collar portion 56 of astud shaft 57 formed with an axial bore 58. The stud shaft 15 formedintegrally with a crank arm 59 at one side of the collar portion 56 andadjacent to the other side of the collar portion, the stud shaft isexternally shouldered and accommodates a bifurcated leaf spring 60secured by a fastening screw 61 to the support plate 40, yieldinglyconstraining the collar portion against the bearing seat.

Pivotally connected to the crank arm 59 by a pivot pin 62 is the upperextremity of a needle bar drive link 63 which is formed at the lowerextremity with an inturned clevis 64 straddling the upper extremity ofthe needle bar 49 and pivotally connected thereto by the pivot screw 52.The needle bar drive link 63 is formed opposite the clevis 64 with arearwardly extending take-up arm 65 terminating in a threadaccommodating eyelet 66 which, as will be described hereinbelow,controls and meters the thread which is directed to the eye of theneedle.

Also endwise slidable in the out-turned arms 46 and 47 is a presser bar70 having a conventional presser foot 71 secured to its lower extremity.A lateral stud 72 secured to the presser bar extends through a guideslot 73 in the support plate 40 to prevent the presser bar from turning.The lateral stud 72 is engaged by one arm of a coil spring 74 of whichthe other arm abuts beneath the block 41 so as to bias the presser footdownwardly. A presser lifting cam member 75 pivoted on the support plate40 may also be disposed beneath the lateral stud 72 by which the presserfoot may be elevated.

The out-turned arm 46 and 47 of the bracket 45 may support a sheet metalguard plate to which is secured a conventional thread tensioning device81 which includes thread tensioning friction disks 82, a conventionalcheck spring 83 and a thread guiding post 84. Thread from a source ofsupply (not shown) is directed to the friction disks 82 of the threadtensioning device 81 looped about the check spring 83 and thence to thetake-up eyelet 66. From the take-up eyelet the thread is directedthrough a thread guiding eyelet 85 formed in a pin 86 adjacent to thethread tensioning device 81, next to a thread guide 87 secured to theguard plate 80, and then to the needle eye.

The loop taker module 13 is assembled on a plate 100, which is drilledto accommodate fastening screws 101 and 102 threaded into the tappedholes 24 and 25, re-

spectively, in the frame 11 by which the plate is secured on the surface19. Preferably, the screw 101 is formed with a shouldered head 103serving to locate the loop taker in sewing position as will be describedhereinbelow. Assembled on the plate 100 and sustained in cooperatingrelation as a unitary module therewith are the loop taker, indicatedgenerally as 104, and the work feeding instrumentalities, indicatedgenerally as 105.

The loop taker is carried by a swinging frame hinged to the plate 100.The swinging frame comprises an upper arm 106 which extends above theplate 106, and a lower arm 107 rigidly secured to the upper arm by aspacer 108. A second spacer 109 secured to the lower arm 107 is drilledand tapped for a headed hinge screw 110 which is extended through boththe plate 100 and the upper arm 106 and bears against the upper arm byway of a spring Washer 111. Encircling the second spacer 109 is a twoarmed wire spring 112 of which one arm bears against the frame arm 16-and the other bears against the spacer 108 to bias the swinging frametoward the plate 100. An abutment 113 formed on the upper arm 106 of theswing ing frame engages the shouldered head 103 of the fastening screw101 to locate the swinging frame in a predetermined operative positionrelatively to the path of reciprocation of the needle 51.

The loop taker 104, as illustrated in the drawings, is carried by theswinging frame and is so disposed thereon as to occupy a positioncooperative with the needle 51 in the formation of stitches when theswinging frame abutment 113 is seated against the shouldered head 103 ofthe fastening screw 101. The loop taker may be of any known orconventional type suitable for the formation of either chain or lockstitches as may be desired. Indeed the novel organization of the sewingmachine of this invention provides for the ready exchange of loop takermodules 13 to substitute one type of loop taker for another. The looptaker illustrated on the accompanying drawin s is a lock stitch formingloop taker which operates in accordance with the principles set forth inmy co -pending United States patent application Ser. No. 439,420 filedMar. 12, 1965, to which reference may be had, which does not requirethat the loop taker be driven in any predetermined timed relationshipwith the needle reciprocation. Moreover, the specific features ofconstruction of the loop taker illustrated in the accompanying drawingsalso forms the subject of my co-pending United tates patent applicationSer. No. 537,065 filed Mar. 24, 1966 to which reference may be had, andtherefore, only that brief description of the loop taker will be setforth hereinbelow as will provide an understanding of the operation ofthe sewing machine of this invention.

Referring particularly to FIGS. 7 and 8, the loop taker 104 takes theform of a rotary hook and includes an inverted conical basket secured bypins 121 to the upstanding collar portion 122 of a belt pulley 123. Thepulley 123 is freely journaled on a bushing 124 surrounding a stationarycylindrical post 125 which is secured, as by a screw 126, to the lowerarm 107 of the swinging frame. Secured, as by a force fit into a shallowcounterbore 127 in the rim of the basket 120, is a flat annular ring 128formed with a plurality of internally extending thread seizing beaks129. A pin 130 set into the basket in a notch 131 in the ring 128 servesto lock the ring for rotation with the basket.

A bobbin case supporting tray 132 is fixed to the top of the stationarypost 125 within the rotary hook basket 120. The stationary tray isformed with a fiat bottom 133 and with two angularly arranged upstandingsidewalls 134 and 135 which support and locate a bobbin case, indicatedgenerally at 136. The bobbin case 136 is formed with angularly arrangedside surfaces 137 and 138 which abut the tray sidewalls and with aflange 139 which overlies the fiat annular ring 128 of the rotary hook.The underside of the bobbin case rests upon the flat bottom 133 of thetray except where the bobbin case is formed with a shallow recess 140shaped generally circular but with a chord 141 extending across oneside.

The upper arm 106 of the swinging frame is formed with an opening 150above the rotary hook which exposes a cavity 151 in the bobbin caseadapted rotatably to accommodate a thread carrying bobbin 152. A springfinger 153 secured by a pivot screw 154 to the upper arm 106 of theswinging frame overlies and bears downwardly against the bobbin 152 andthus also biases the bobbin thread case upon the stationary tray 132. Aleaf spring 155 carried on the upper arm 106 also engages the bobbincase side surface 138 serving to constrain the bobbin case yieldingly inposition within the rotary hook.

The loop taker module may also carry the work feeding instrumentalitiesof the sewing machine particularly wherein a drop feed is desired suchas that illustrated particularly in FIGS. 5, 6 and 7. It is pointed out,however, that using the module concept of construction as taught by thisinvention, other forms of work feed mechanism might be used as, forinstance, a top feed mechanism carried by the needle module 12 might beemployed.

Referring to FIGS. 5, 6, and 7, the drop feed mechanism 105 includes afeed dog 160 arranged beneath the presser foot 71. The forward extremityof the feed dog rests upon the plate 100 and in the rearward extremityis formed with a notch 161 embracing the upper portion of a rock arm 162which is fast on a rock shaft 163. The rock shaft 163 is journaled inspaced bearing lugs 164 downturned from a bar 165 which is supportedbeneath the plate 100 by two spacers 166. A throat plate 167 formed withslots 168 accommodating the feed dog and with a needle aperture 168' issecured to a vertical stud 169 which is slidable vertically in a hole170 in the plate 100 and a hole 171 in the bar 165. Pivoted to the stud169 on a pin 172 is a lever 173 to which is pivoted, as at 174, afulcrum roller 175 which snuggly fits between the underside of the plate100 and the bar 165. Movement of the lever 173 causes the throat plateto rise and fall alternately to cover and to expose the feed dog throughthe throat plate slots. Oscillation of the rock shaft 163 serves toreciprocate the feed dog along the throat plate slots. Operation of thefeed mechanism, therefore, requires simply that rocking movement beimparted to the lever 173 and that related oscillatory movement beimparted to the rock shaft 163.

The means for imparting such related operative movement to the feedmechanism as well as for imparting turning movement to the loop takerand to the needle bar driving crank are provided in the actuating module14 which will now be described.

The actuating module 14 is assembled on a supporting plate 180 which isaflixed to the connecting limb 17 of the frame 11 by the aforementionedfastening screws 22 and 23. As illustrated in FIG. 4, the supportingplate 180 is formed near the top with a concave bearing seat 181 havingthe shape of a spherical section.

A bushing 182 having a spherically shaped peripheral portion 183accommodated in the bearing seat 181 is formed with an external shoulder184 upon which a bifurcated spring 185 engages to hold the bushingresiliently in the bearing seat 181. The spring 185 is secured to theplate 180 by a headed adjusting pin 186 which passes through the plate180. A finger grip 187 projects from the headed pin 186 so that themachine operator may at will change the angular position of the pin 186,and at the opposite side of the plate 180 the pin 186 has secured to ita collar 188 formed with a diametrical slot 189 for regulating the feedstroke of the work feeding mechanism.

Journaled' in the bushing 182 is a shaft 200 adapted at the freeextremity to be accommodated in the axial bore 58 of the stud shaft 57on the needle module 12. A fiat 201 formed on the shaft 200 may be usedin cooperation with a set screw 212 threaded into the stud shaft 57 tosecure the stud shaft onto the shaft 200. A

counterweight 203 may also be provided fast on the shaft 200 to minimizevibration of the sewing machine.

Secured to the shaft 200 by a set screw 204 is a feed driving eccentric205 which in the assembled relation of parts is spaced from the bushing182 by a collar 206. Secured to the eccentric 205 by screws 207 is ahandwheel 208 formed with two annular belt pulley grooves 209 and 210.The belt pulley groove 209 accommodates a drive belt 211 from anysuitable source of power, such as for instance, as a drive pulley 212 onan electric motor 213 supported on a bracket 214 secured by screws 215to the plate 180. The belt pulley groove 210 accommodates a drive belt216 which runs over a pair of idler pulleys 217 and 218 carried on theplate and is directed about the pulley 123 on the loop taker 104.Preferably using the thread manipulating and stitching instrumentalitiesillustrated in the drawings, the handwheel pulley 210 is three times thediameter of the pulley 123 on the loop taker so that a speed ratio ofapproximately three revolutions of the loop taker will be maintained foreach reciprocation of the needle.

For driving the work feeding mechanism, the feed driving eccentric 205is embraced by two pitman straps 220 and 221 which, as illustrated inFIG. 3, extend substantially at right angles to each other. The pitmanstrap 220 extends substantially vertically downward and is pivoted to acylindrical boss 222 formed on a vertical link 223 which is constrainedto move in a slot 224 in the supporting plate 180. At the lowerextremity the link 223 is formed with a lengthwise slot 225 along whichas extension abutment 226 may be selectively clamped between nuts 227and 228 on a headed fastening screw 229. The extension abutment 226 maybe formed with an inturned tang 230 extending into the slot 225 toprevent the abutment from turning. The fastening screw 229 extendsthrough a Vertical guide slot 231 formed in the plate 180.

FIG. 5 illustrates the position of parts when both the actuating module14 and the loop taker module are assembled on the frame 11. The feedlift lever 173 will pass through the guide slot 231 beneath the abutmentextension 226. A tension spring 232 arranged to act between the lever173 and an anchor pin 233 fixed in the plate 182 biases the lever 173into engagement with the abutment extension 226.

Referring to FIGS. 3 and 5, the feed advance rock shaft 163 extendsthrough an aperture 239 in the plate 180 when the parts are assembled onthe frame. A rock arm 240 is secured to the rock shaft 163 by a setscrew 241. A link 242 pivoted to the rock arrn 240 by a pivot pin 243 isalso connected by a pivot pin 244 to the pitman strap 221 which extendsgenerally horizontally from the feed eccentric 205. Journaled on thepivot pin 244 is a slide block 245 which is constrained to move alongthe diametrical slot 189 in the collar 188. Adjustment of the angularposition of the slot 189 by means of the finger grip 187 will determinethe direction in which the work will be fed and the length of the feedstep at each stitch.

In assembling the sewing machine of this invention, the support block 30of frame 11 may be secured to a base 250 or to a table, carrying case,or the like as is desired. The actuating module 14 is then secured inplace by the screws 22 and 23. The loop taker module 13 is then securedin place using the screws 101 and 102 taking care that the feed liftlever 173 is inserted through the slot 231 and the feed lift rock shaftis inserted into the bore in the rock arm 240 in the actuating modulesupport plate 180 when the spring 232 is attached to the feed lift lever173. The set screw 241 is tightened to complete the feed advanceconnection, and when the belt 216 is entrained on the pulleys 123, 210,217, and 218, the loop taker and work feed mechanism will be operativelyinstalled on the frame.

The needle module 12 is then installed simply by placing the bore 42 ofthe block 41 on the cylindrical portion 18 of the frame arm andsimultaneously inserting the shaft 200 in the axial bore 58 of the studshaft 54. The support plate 40 of the needle module 12 may then beturned and slid axially upon the cylindrical portion 18 of the frameuntil the needle 51 is accurately aligned with the needle aperture 168of the throat plate on the loop taker module in place. The set screw202. is then tightened to connect the needle lbar drive and the sewingmachine will be completely assembled.

Since the stud shaft 57 is accommodated in a spherical bearing seat 55in the support plate 40 of the needle bar module, and the bearing seat181 for the shaft 200 in the supporting plate 180 of the actuatingmodule is similarly spherical, conisdera'ble variation in the relativepositions of the support plates 40 and 180 on the frame 11 may beaccommodated without binding of the shaft 200. The construction of theneedle thread take up arm 65 as an integral part of the needle bar drivelink 63 makes possible this advantageous utilization of theself-aligning bearings 55, 181 because this take up constructionobviates the need for any anchor pivots or anchor links between the takeup arm 65 and the supporting frame as exist in conventional link typetake-ups. A shaft which drives a conventional link take-up having apivot pin or anchor link connection with the machine frame must bemanufactured in predetermined spacing and alignment with the pivot pin-or anchor link connection, which requirement in the present inventionwould obviate the advantages of the self-aligning bearings 55181.

Referring to FIGS. 2 and 10, it will be noted that the take-up arm 65projects toward the rear of the sewing machine substantiallyperpendicularly from the needle bar drive link 63 at a point oppositethe pivotal connection provided by the pin 52 with the needle bar.Moreover, the distance of the take-up eyelet 66 from the pivot pin 52 isapproximately twice the distance between the pivot pins 52 and 62. Withthis construction, as illustrated in FIG. 10, the path of the eyelet 66on the takeup arm is a flattened figure eight oriented substantiallyparallel to the axis of the needle bar 49. Optimum efficiency of threadmetering will thus be obtained relatively to the checkspring 83 aboutwhich the thread approaches the eyelet 66 and the thread guide eyelet 85to which the thread extends from the eyelet 66.

As ilustrated in FIG. 10, the path of motion of the take-up eyelet 66substantially parallel to the axis of the needle bar makes possibleeffective and convenient shrouding of the operating mechanism on theneedle bar module 12 by a cover plate 250 which may follow thefunctional substantially rectangular outline of the support plate 40,without the requirement 'for flanges, lips, 'or extensions, in order toshroud the movement of the take-up arm 65.

The graph ilustrated in FIG. 11 indicates the co-operative relationshipbetween the manner in which the needle thread is metered by the take-upeyelet 66- and the demands of the stitch forming instr-umentalities uponthe needle thread during stitch formation. This graph plots as abscissathe needle bar crank angle, and as ordinate the total lengths of threadon the one hand as made available by the take-up, and on the other handas demanded by the stitch forming instrumentalities including the rotaryhook 104 which is driven at approximately three revolutions for eachneedle reciprocation. The curve illustrated in dashed lines and labeledTAKE-UP indicates the thread made available at each crank angle by thetake-trpwhile the curve illustrated in solid lines indicates thecorresponding thread demanded by the stitch forming instrumentalities.

As described hereinabove, the loop taker 104 is preferably of the typein which the motion imparted to the needle loop seizing beaks 129 neednot be timed precisely relatively to the needle reciprocation, it beingimmaterial to stitch formation which of the beaks 129 seizes the needlethread. The thread demand curve in FIG. 11, therefore,

from the points A and B to the points C and D widens into an area orfamily of parallel curves depending at each stitch upon the actual timeat which loop seizure occurs. Similarly from the points C and D to thepoint E the demand must be represented by a family of curves since thecast off of the thread from a stored position on the bobbin case may beinfluenced by the actual time at which loop seizure occurs.

Whereas in conventional lock stitch sewing machines in which the looptaker is driven in precise timed relation with the needle reciprocation,the take-up need satisfy only one predetermined thread demand, in themachine of the preferred form of this invention, the take-up mustsatisfy whichever one of the family of different thread demands mayoccur. As illustrated in FIG. 11 the thread supplied by the take-up ofthis invention adequately incompasses the entire range of thread demandswhich are imposed by these stitch forming instrumentalities.

Having thus set forth the nature of this invention, what I claim hereinis:

1. A sewing machine comprising a C-shaped frame having spaced framearms, an accurately machined straight cylindrical portion at theextremity of one of said frame arms, an accurately machined flat slabbedsurface on the other frame arm parallel to the axis of said straightcylindrical surface, a first and a second module each including abracket and a movable stitch forming instrumentality carried one on eachof said brackets, means for securing said first and second modulebrackets each on a respective one of said two accurately machined framesurfaces in positions arranging said stitch forming instrumentalitiescomplemental toeach other for cooperation in the formation of stitches,said means including an accurately machined straight cylindrical borefonmed in said first module bracket complemental to said straightcylindrical portion, and an accurately machined flat seat formed on saidsecond module bracket complemental to said slabbed surface, a thirdmodule including a bracket and a driven actuating element carriedthereon, means for securing said third module to said frame unit remotefrom said two accurately machined surfaces, and means operativelyconnecting said driven actuating element with at least one of saidstitch forming instrumentalities, the stitch forming instrumentalitycarried on said first module bracket comprises a thread carrying needlesupported for endwise reciprocation in a path extending transversely ofsaid cylindrical bore, and in which the stitch forming instrumentalitycarried on said second module bracket comprises a loop taker, a needlereciprocating crank journaled in said first module bracket, a drive linkconnecting said crank with said needle bar, in which said meansoperatively connecting said driven actuating element with at least oneof said stitch forming instrumentalities includes shaft meansoperatively connecting said driven actuating element with said needlereciprocating crank, self-aligning bearing means in each of said firstand third module brackets defining an axis of turning movement of saidshaft means, and in Which a needle thread take-up arm extends laterallyfrom said drive link and is formed at the free extremity with a threadengaging eyelet.

References Cited UNITED STATES PATENTS 683,847 10/ 1901 Catenacci112-230 1,062,696 5/1913 Cox 112-181 1,129,588 2/ 1915 Onerdon-k 112-2411,387,677 5/1921 Hemleb 112181 1,396,040 11/1921 Herr 112182 1,468,3199/1923 Nelson 112-484 1,593,250 7/ 1926 Echandia 112-220 1,708,296 4/1929 Greenwood 112258 2,633,092 3/1953 Robert 112---220 (Otherreferences on following page) 9 10/ 1953 Reinhold 112258 5/1957 Francois112-258 12/1961 Leslie 112258 FOREIGN PATENTS 2/ 1954 Great Britain.2/1955 Great Britain. 7/ 1942 Germany.

1 0 345,526 9/1960 Switzerland. 374,273 2/ 1964 Switzerland.

HERBERT F. ROSS, Primary Examiner.

US. Cl. X.R.

